sldpt ... is it initialized outside your loop?
You increment it towards the bottom but it has no initial value
Get rid on the searchcursor and replace it with a SelectLayerByAttributes
arcpy.SelectLayerByAttribute_management("your_featureclass", 'NEW_SELECTION', '"Field_10" == 1')
Since it appears the searchcursor is only looking for values of 1 in what I assume is your duplicates field (SCO1R (?)).
Once the selection is made, only the selected records will be processed.
Are you then are checking to see if field2 ==field3 (source and sink)
and if so, are you then switching the source and sink and updating fields 8, 9 and 13 with new values, and incrementing the sldpt by 1.
Not sure what preceeds this, but applying a selection and working with it will get rid of one cursor.